VPSA (vacuum pressure swing adsorption)

A Global Fund briefing note (4 March 2025) describes two air-handling elements, a lobe compressor and a vacuum pump, with the lobe compressor pushing air into two sieve bed tanks at approximately 0.5 bar gauge. The note adds that, like PSA and VSA, VPSA produces oxygen of approximately 93%, and that at least one additional oxygen compressor is needed for direct piping; in its description, a scroll compressor raises the oxygen to 5 bar.

The note lists a lower average power consumption than PSA, but also reports of low purity with these systems and additional compressors that add potential failure points, and it says some manufacturers consider the technology more appropriate for larger industrial applications. WHO describes VPSA as generally preferred when large-scale production is required, and as a significant cost investment because of the complexity of its configuration. See PSA, VSA and VPSA compared.